Rheumatoid factor determinants immunoglobulins

Mechanism of Action. The basis for the antiar-thritic effects of penicillamine is unknown. Reductions in serum immunoglobulin M-rheumatoid factor have been observed with penicillamine, and this drug has been shown to depress T-cell function.53 These and similar findings suggest that penicillamine works by suppressing the immune response in rheumatoid arthritis, but the exact mechanisms remain to be determined. 

Macromolecular substances with multiple antigenic determinant [Ag] can be determined by agglutination of particles which are coated with specific antibodies [Pa-Ab Ag Ab-Pa]. This method can detect immunoglobulins, human placental lactogens, a-fetoprotein, etc. The sensitivity is approximately 10 (xg/liter. Alternatively, antigen-coated particles are used these particles agglutinate with antibodies. Thus, antibodies can be determined by this system. Cambiaso et al. reported automated determination of immune complexes by their inhibitory effect on the agglutination of IgG-coated particles by rheumatoid factor or Clq (C3). 

In a nested case-control study in Mexican patients with rheumatoid arthritis encompassing 1274 patient years, the risk factors were determined for acquiring infectious diseases (378). In addition to the cumulative doses of methotrexate and the duration of corticosteroids use, the mean daily dose of penicillamine was a risk factor. In one patient the infection was secondary to neutropenia. Tests for a possible immunoglobulin deficiency were not performed. 

---